Convert range of cells to comma separated list

I need to take the range of cells from C2:C50 and extract each cell's contents and convert them into a list of values separated by commas. The new list can be copied to the clipboard or inserted into a new cell.

For example: C1 = 50, C2 = 23 ---------convert to "50,23"

I'm doing this, because I need to use these values as query criteria in Access 07. Usually I will just paste the values into a new table and join on the field(s) needed for criteria, but in this case I think the best way to run this query is to "hardcode" the values into the actual SQL statement.